Clean up module documentation (#36909)

* Clean up module documentation

This PR includes:
- Removal of `default: None` (and variations)
- Removal of `required: false`
- Fixing booleans and `type: bool` where required

* Fix remaining (new) validation issues

lib/ansible/modules/cloud/cloudstack/cs_region.py

@@ -41,18 +41,13 @@ options:
     description:
       - Name of the region.
       - Required if C(state=present)
-    required: false
-    default: null
   endpoint:
     description:
       - Endpoint URL of the region.
       - Required if C(state=present)
-    required: false
-    default: null
   state:
     description:
       - State of the region.
-    required: false
     default: 'present'
     choices: [ 'present', 'absent' ]
 extends_documentation_fragment: cloudstack